You are here

Arkansas Winegrowers Battle Mold, Black Rot

FORT SMITH — Arkansas grape vines took a hit in the spring with a late freeze, but what survived has been susceptible to mold and black rot.

With the steady rains in western Arkansas in recent weeks, winemakers are pulling all the tricks they have to fend off plant diseases caused by wet and humid conditions.

In addition to five rounds of ice storms and hail storms, a late spring freeze reduced Post Familie Vineyards’ grape crop by about 10 to 15 percent, says Thomas B. Post in Altus. Other Arkansas vineyards have seen as much as a 20 percent impact from the wet weather.

“Other than that we’re looking good this year,” Post said. “It’s a little weedy though with all the extra rain. It could be better, but it could’ve been a lot worse.”

At neighboring Chateaux Aux Arc, Audrey House was able to stave off much of the damage from the “blood moon” late freeze in mid-April with a blanket of smoke using debris from the previous ice storm. But the consistent rains and high humidity has given her vines, and her tractor, other troubles. She got stuck one day in the mud which kept her from spraying a JMS Stylet-Oil as a mold repellent.

“The conditions have been perfect for mold and mildew and black rot,” House said. “This is a growing year for the vines though, and we needed that recovery after the droughts because we had to cut back a lot of dead wood last year from the droughts in 2011 and 2012.”

To combat mold, mildew and pests, Post is using a new pesticide-free method with ozone water from AgriOzein, developed by Ernie Wilmink in Lindsay, Neb.

“It does work,” Post said. “But he’s had to redesign the air system a little to work with the muscadines. They have a denser canopy.”

Post said because of the heavier amount of rain in Arkansas, winegrowers must spray anti-fungal agents three to four times more often than those in California.

John Trickett of Circle T Winery & Vineyards says his vines near Booneville also have experienced a hard dose of black rot.

“Two weeks ago I had more healthy fruit than I’d ever seen,” Trickett wrote recently. “Then June turned atypical. It never got warm, we rarely saw the sun, and all the rain we should have had in the spring happened in mid- to late June.”

Trickett’s grape crop has been “substantially reduced” by disease and “conditions overwhelmed the potential.”

“If we’d had a normal year temperature wise, the fruit would have gone through veraison (fruit changing color and the canes turning woody), which would have made it immune to that by now,” Trickett added.

Insects are expected to be a problem later in the year.

Barbara Lewis, an entomology professor at the University of Arkansas, said Arkansas wine growers are well informed on insects that could harm their crops and do a good job of maintaining their vines. If not maintained though, a grape berry moth, for example, could reproduce four generations before it is controlled, she said.

So far, Lewis has not heard of any Arkansas winegrowers having issues with a fairly new invasive species, the Asian fruit fly called spotted wing drosophilia. The Japanese beetle and “stink” bug numbers have also been low this year also so far, she said.